Are betaine, inositol, L-lysine (L-lysine hydrochloride) and L-arginine safe for children to use as supplements?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: October 30, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Safety of Betaine, Inositol, L-lysine HCl, and L-arginine Supplements for Children

L-arginine supplementation may be used safely in children for specific medical conditions, while betaine, inositol, and L-lysine supplements have limited safety data but appear generally safe when used appropriately under medical supervision.

L-arginine

Safety Profile

  • L-arginine supplementation is conditionally recommended for prevention of necrotizing enterocolitis (NEC) in preterm infants (Level of Evidence: 1-, Recommendation Grade B) 1
  • Oral L-arginine supplementation has been studied in children with pulmonary arterial hypertension, showing hemodynamic benefits without significant systemic hypotension 1
  • L-arginine serves as a substrate for nitric oxide production, which is important for vascular function and glucose homeostasis 2, 3

Dosing Considerations

  • For preterm infants, L-arginine has been studied at doses of 1.5 g/10 kg body weight per day 2
  • In studies of pulmonary arterial hypertension, oral L-arginine was administered at 0.5 g/10 kg body weight for acute effects and 1.5 g/10 kg body weight per day for longer-term treatment 1
  • Typical therapeutic doses range from 1.2 to 6 g per day in clinical settings 3

Precautions

  • Potential drawbacks of arginine supplementation may include increased concentration of polyamines, which are proproliferative 1
  • Long-term effects of L-arginine supplementation in children have not been thoroughly studied 1
  • Should be used under medical supervision, particularly in children with cardiovascular conditions 3

L-lysine HCl

Safety Profile

  • L-lysine supplements are generally considered clinically safe with no reported toxicity in children 4
  • The provisional no-observed-adverse-effect level for L-lysine is 6000 mg/person/day based on adult studies 5
  • L-lysine has been used to enhance growth and development in children, particularly in developing countries with cereal-based diets 4

Side Effects

  • Side effects are primarily limited to subjective gastrointestinal tract symptoms such as nausea, stomachache, and diarrhea 5
  • Integrated analysis of gastrointestinal symptoms showed no significant increase in risk (risk ratio 1.02,95% CI 0.96-1.07) 5

Precautions

  • Excessive intake of L-lysine can lead to amino acid imbalance, potentially suppressing intended benefits 4
  • Should be used with appropriate precautions and preferably under medical supervision 4

Betaine and Inositol

Limited Evidence

  • Specific safety data for betaine and inositol supplementation in children is limited in the provided evidence
  • Neither supplement is specifically mentioned in pediatric guidelines for routine supplementation 1, 6

General Considerations for Supplement Use in Children

Prevalence and Patterns

  • Approximately one-third (31-34%) of children in the United States use dietary supplements 7, 8, 9
  • Multivitamin-mineral products are the most commonly used supplements (23.8%), followed by omega-3 (19.3%) and immune support products (9.4%) 8, 9

Medical Supervision

  • Only a small percentage (15%) of supplements used by children are based on recommendations from healthcare providers 7
  • Most supplements used by children are not under medical supervision, despite limited scientific data supporting their use in nutrient-replete children 7

Factors Influencing Supplement Use

  • Supplement users tend to be non-Hispanic white, have higher family incomes, report more physical activity, and have health insurance 7
  • Significant relationships exist between supplement use and child's age, body weight, BMI, parents' education level, healthcare worker status, and economic status 9

Safety Recommendations

  • Nutritional needs should generally be met through food consumption according to dietary guidelines, with only a few supplements specifically recommended for children under particular conditions 8
  • Parents should consult healthcare providers before giving supplements to children, as inappropriate use may lead to nutrient intake above recommended upper limits 8, 9

Conclusion

  • When considering these supplements for children, medical supervision is strongly recommended
  • Benefits should clearly outweigh potential risks, particularly for L-arginine and L-lysine which have more established safety profiles in pediatric populations 1, 4
  • Monitoring for gastrointestinal side effects is prudent, especially when initiating supplementation 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Arginine Supplementation in Neonates with Necrotizing Enterocolitis

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Effects of Citrulline and Arginine Supplementation

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Aminoven Dosing in Neonates

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Why US children use dietary supplements.

Pediatric research, 2013

Research

Use of Dietary Supplements and Influencing Factors in Children.

International journal of environmental research and public health, 2024

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.